Compound metal body and process of producing same.



PATENTED JULY 21, 1908.

DUOING SAME.

INVENTOR 9a.! ATTORNEYS7 J. F. MONNOT. Y AND PROCESS OF PRO APPLIOATION FILED APB.. 24, 1907.

GOMPOUND MB'IYAL BOD WITN ESSES:

- citizen of UNITED ST1/uurs IIUATENT. OFFICE.

JOHN F. MONNOT, OFA NEW YORK, N. Y., AssIGNoR' To DUPLEX METALS COMPANY, oF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

co'lrroUND nur. BODY AND rnocnss or FR Original applioaon 1011 'September 8,

Tb all'whom 'it may concern: 1 l Be itknown that I, JOHN F. MoNNo'r, a the United States, residing at New York, in the county of-New York and State of New York, have invented certain new 'and useful Improvements in-Com ound f Metal Bodies and Processes of Pro ucing Same; and I do hereby declare the followmolten condition mgto be a`full, clear, and exact description as will enable others of the same, such skilled inthe art to which it appertains to make and use the same.

invention relates to compound metal bodies and processes of and consists in metal layers of silver u'nited to unlike metals, and particularly to ferrous metals, such asv iron or steel (including the steels), by an intermediate layer of a third metal; lalso in theprocess of producing such articles.

The present application is a division .of my prior application filed-Sept. 6, 1906, Sr, No; 333,570, and on which has issued Pat-` ent No. 853,716, dated May 14, 1907, said application itself based on an earlier application filed June 16,-1905,-Sr. No. 265,508, in both of which rior applications the subject matter of t invention is substanarticles composed of 'tially disclosed, butnot specifically claimed.

It is well known that it is very difficult to unite, permanently, silver to ferrous metals, such as wrought iron and the various steels, and. to nickel, cobalt, and certain other metals. In my said prior applications I have set forth a discovery made by me, which is that' the lack 'of affinity between silver and such unlike metals, which exists at all common temperatures, and which renders it'diflicult to unite them by any of the own processes, although existing at 'the common casting temperature of silver, disappears when the silver is raised to a temperature much above its melting telnperature. Copper also has the same ualitly, as has gold and certain other meta s. o the condition of such metals and other metals .having the same property, in which they become capableof entering into permanent union with iron, steel and like ferrous metals, I have applied the term superand in my said Patent No. 853,716. I have process of.uniting such unlike metals involv- Specication of Letters Patent'.

1908, Serial No. 888,570. Divided and this application led April 24, 1907.

' Burial No. 389,995.

solidify producing the same various compound 'electrical condnctivit lsectional view of one claimed broadly the ODUCING SAHE.

Patented July 21, 1908.

ing the b lng of one of them to the supermoltencondition. Y In another application for Letters Patent, Ser. No. 367985, filed April 13, 1907, I havedescribed and claimed` a process -of uniting silver to iron and other e metals, consisting in contacting supermolten -silver with such unlike metal and causing a `portion of such molten metal to thereon. There are tions, however, to keeping molten condition recious metals,-such as silver, gold, etc.," t e principal objection being that since in the su ermolten condition the vmetals aren very sulliject to contamination or oxidation or deterioration of various sorts, there is apt to be considerable loss of precious metal. It is therefore preferable to form the union between silver and the unlike metal to which it is to be united, by means of a third cheaper intermediate metal having, like silver, thequality of uniting with e at the supermolten -lron and the lik condition, and with which silver at substantiallyA ordinary casting' temperature will unite readily. Copper is one such metal, the qualities of which particularly fit it for uniting silverto iron and the like for it is highly ductile and malleable, and has high In another a pilication, Serial No. 368,770, filed Apri 17, 1907, I have'claimed the process of uniting other metals to iron and the like'by means of an intermediate metal such as copper. Therefore in this case I do-not claim such process broadly, but only the species thereof involving the use of silver.

In the accompanying drawin s I illustrate apparatus such as may be use in carrying out my said process.

In said drawings: Figure 1 represents a form of apparatus for carrying out the said process. Fig. 2 shows in detail section the construction of the bottom plate and lower portion of such apparatus. Fig. 3 shows a sectional view of another form of casing which may be emlplo ed.

n ig. 1, lis a prelimina heating chamber for the ingot or core, 2 axfilrnace for heating a crucible 3, containing a body of supermolten coating metal. 5 designates a power hoist, here shown as an electrical hoist, mounted on a suitable track so that it can be moved from place to place; and from said the casing of hoist is suspended, by means of a orter bar 6, the in ot 7, which is the obJect to be coated. aid ingot is shown surrounded by a' casin 8 having an internal diameter slightly Iarger than the external diameter of the ingot, and to said casing is connected a pipe 9, a portion of which is flexible, said pipe provided with a three-way valve 10.

. secured to the ingot 7 itself, by means of a screw 13. Said bottom plate is provided with a raised rib or ring 14 matching a corresponding groove 15, in the lower edge of the casing, and adapted to coact with said groove to make a tight joint. For raising and lowering the casing 8 with respect to the ingot 7, a special hoist 16, suspended like orter bar 6 from hoist 5, is provided. It as, in the form shown, two winding drums 17 upon which are wound cables 18 connected to opposite sidesof the casing, so that said casing may be raised and lowered truly vertically.

I customarily provide the crucible with a loose removable cover 19, which cover is designed to exclude air from the molten metal so far as possible, and is removed only when and so long as necessar to lower an ingot and casing into the cruci molten metal, or for similar reason. To further exclude air from the surface of the mol-- ten metal, I cover so much of its surface as possible with a layer of charcoal, a ring 20 of refractory material which floats on the surface of the molten metal servinglto maintain a clear space in the center for t e passage of the ingot and casing. To assist in forming a tight joint between the bottom plate and casing, I provide in the groove 15 at the bottom of the casing acking material 21.

As an alternative to the above described apparatus for carrying out my rocess, I may use that shown in Fig. 3, whic is much the same as that above described exce t that the casing 6 is provided with inlets 23 in its sides, said inlets arranged to be closed at will by a sliding shield or valve 24. In carrying out the process with this `apparatus the casing without the bottom plate 12 thereon is place over the heating chamber 1, said casing being at the time filled with a protective atmos phere as above described, and the porter bar 1s lowered down through the casing, secured to the ingot or core to be coated and raised up into said casing again with the said ingot or core. The casing with the core 7 within it, is then moved to one side, the bottom plate 12 applied, and then the casing is le, or to inspect the moved over the crucible 3 containing supermolten coating metal, and is lowered into said supermolten metal; the valve or closure 24 being raised as the openings 23 come to the surface of themolten metal so that said casing fills through said openings 23. The casing with ingot and molten metal within it is then raised and the molten metal allowed to cool as before. In carrying out the process in this ap aratus, the protective atmosphere within t e casin when the filling holes 23 are open, protects t e surface of the ingot and the molten metal which enters the casing against oxidation; and in fact no air can enter the casing, because the holes 23 are submerged in the molten metal almost instantly after the closure 24 is raised, and during the possible brief instant while said openings are open but not completely submerged the outrush of gas from the casing will prevent the entrance of air.

To hasten the filling of the casing with molten metal, and to prevent trapping of as in the molten metal as it solidiies, I re erably apply suction to the outlet 25 o' 10, having first set said valve so as to cut off the entrance of gas'and to place outlet 25 in communication with the interior of the casing. This is done, however, only after the molten metal has commenced to flow in. And when necessary or expedient, I reduce the fluid ressure upon the oint between the bottom p ate and casing, w ile raising either the casing shown Fig. 1 or the casing shown in Fig. 3, by applying suction to the outlet 25 of valve 10.

`The coated ingot produced in either of the ways above described is usually worked, as

.by rolling (either at once, or after submission to a soaking heating to bring all the parts to a uniform temperature), to condense the metal of the coating and to extend it to shapes desirable for future working, such as bars, rods, and plates. In such ture of union between them and the final article usually contains the vsame relative roortion of coating and base as the {inis ed ingot. v

The core or p scribed in this speciiicatioiineed not be iron or steel, but formost purposes an iron or steel base or core will be preferred. Hence in certain of the following claims I specify steel as the metal of such core or base; and this term steel I employ generically to designate all forms of iron, including not merely ordinary carbon steel, both low-carbon or mild and high-carbon or hard, but also wrought iron (the properties of which are nearly identical with those of mild steel) and various compound steels, such as tungsten steel, titanium steel, vanadium steel, chrome steel, nickel steel, manganese steel, cobalt steel; also substantially pure iron,-

extension the joined metals extend together without rupbase vGringotIcoated as dej bod ' tion, I app y z'. e., the'chemical element Fe, substantiallyv free from carbon and other metalloids or immg lngredients.

-purities and modify In the methods of uniting silver and iron or steel above described, the excessiv/elyhi rh temperature of the abuting layers of unli e metals exists only tem orarily as the heat of the molten metal-.K soa into the steel core, while the heat of the molten metal is transferred outwardly by the cooling of the casing walls, and no opportunity is 'afforded for detrimental action upon either the main of the steel or that of the molten metal. Suc changes as take place, or may take place, in either metal, are only in the excessively thin joining layer between; and since, as already explained, I do not limit myself to any theory of how the union between the unlike metals takes place, therefore I do-not assert 1positively, that when the operation is proper y performed, any change of the two metals, or either of them, at the point of juncture, actually takes place. As previously explained, the time of `contact of the steel and silver or other coating metal used, while such silver or other coating metal remains in the supermolten condition, is very.brief, for long contact of the two metals with the gold or other,` coating metal in the very high reactive condition afforded by the supermolten temperature, would of course be detrimental to both. By limitin to a few seconds the period of contact of t e metals while one of them is in the supermolten condition, I limit to extreme thinness the joining layer of alloyed, mixed, interpenetrating, or otherwise molecularly-united metals, the layer which links the core metal and the fused-on layer of coating metal.

The steel coated in any of the foregoing ways possesses a cohering, as distinguished from an adhering, layer or stratum of silver which can be drawn, beaten or rolled together with it at ordinary steel Working temperatures Without parting, even in the est of wire, or in thin leaf. In an ingot so clad, a cutting tool', such as a cold chisel, re-

ses to discover or follow the line of union,

veering off into the softerl metal; and heat-v ing and sudden quenching donot se arate the joined metals. The ad'acent mo ecules of the joined metals mutu same sense inwhich the silver molecules cohere among themselves or the iron molecules cohere to each other.

Accordin to the process of this applicathe coating in two operations, film-coatmfr the ingot 7 by immersin it momentariIy in the supermolten meta in crucible 3 and then, without lowering the casing into the supermolten metal, withdrawlng the ingot, now covered with a thin film-coating formed by the action of the supermolten metal, back into the casing, moving said casing over the crucible 4, the

y cohere in the if the supermolten metal metal unlike both molten metal in which is preferably at the ordinary casting temperature or thereabout, applying the bottom late to the ingot, lowering said ingot into t e metal of bath 4 and thereafter lowering the casing and so confining against the film-coated surface a' layer of the metal from bath 4, and then withdrawing the casing with its contents from the molten metal and permitting the molten metal within it to solidify. 0r, instead of using the apparatus of Fig. 1, that of Fig. 3 may be used; the consequent 4variation in the procedure just described being obvious.

In carryin on theA process in two steps, as above descri ed, the supermolten metal of bath 3 will ordinarily be some cheaper metal than silver which has the power of combining with iron or steel or other metal of which the base is composed, when in the supermolten condition, and j with which the silver will combine at or near ordinary casting temperatures; copper for instance, though silver may be used. Employing a third metal in the supermolteribath is, in fact, quite advantageous, for the reason that metals exposed to air or furnace ases or other contaminating influences whe in the supermolten condition are very rapidly contaminated which, be a precious metal, such as gold or silver, may add materially to the cost of the process, because of the waste of expensive metal involved. By employing a less ex ensive metal, possible oss due to contamination of the metal is greatly reduced. Silver at ordinary casting temperature will unite readily with a copper coating formed from supermolten copper, so as to be as inseparable from the copper as the co per is from the iron or other base; and the thickness of the copper layer may be so slight as to be almost inappreciable, and quite inappreciable in the extended product. Copper and silver both having meltinvr points around 1800 F., and both being (Iuctile and malleable at all lower temperatures, the compound metal body can be conveniently worked at steel working temperaitures and in much the same manner as stee It will of course be obvious that instead of applying a film-coating' of copper or other the base metal and the metal of the main coating, I may apply a film-coating of silver and then form on such m-coating a further coating of silver as above described. Thishas the disadvantage of requiring silver to be maintained at supermolten condition which, however, is not so objectionable when the main portion of the coating is formed from metal at lower temperature; the metal used in forming the film coating being inconsiderable in amount as compared with that used in forming the main coating. A For some purposes, also, it is preferable to apply the silver by a two-step operasuch as copper, the

` I tion instead of by asingle-step operation. '.llie process of coating a ferrous metal by [ihn-coating the same with super-molten untion, by dip likemctal and then forming a further coating on such film-coating, is claimed in my Patent No. 8537161,-above mentioned.

The supermolten temperature of silver is from 2.2,5009 to 2800 F. or higher, as near as I am abley to measure it; all measurements of such extreme temperatures being exceedingly unreliable, as well known; and that of copper is substantially the same. It 1s easy to determine when the supermolten or filmcoating bath has reached the desired condiing a test piece into the bath and then witllidrawing it and permitting the film-coating on it to solidify under conditions precluding oxidation. If the metal is at the propel' temperature, the test iece will be found to have a coating whic cannot be stripped off. In practice it is not necessary to make such test, or to measure the temperature, as the workmen soon become able to tell by surface a pearance when either silver or coppenis in tffe supermolten condition.

Instead of using silver itself for the outer coating I may use silver-containing mixtures or alloys, such for example as silver bronzes.

I intend the teim clude the commercial mixtures consisting principally of silver but containing slight proportions of other metals (usually added to harden the silver) and commonly termed silver. Coin silver is an example.

In an application filed June 19, 1908, Sr. No. 439,284 I have claimed compound or clad metal articles comprising a coating of copper, silver, gold, aluminum and like metals, alloyed with ferrous metals, weld united to ferrous metals, and a process of making such articles.

What I claim is 1. The rocess of producing compound bodies of si ver and an unlike metal inseparably united, which consists in contacting a body of such unlike `metal with a su ermolten mass of another unlike metal andt en contacting the coating formed by such supermolten metal with a mass of molten silver and causin alayer thereof to solidify thereon.

2. T e process of producing compound bodies of unlike metals united together, which consists in contacting a surface of one such metalwith a supermolten mass of an unlike met'al and then contacting the coating formed by such supermolten metal with a molten mass containing silver and causing a layer thereof to solidify thereon.

' 3. The process of producing compound bodies of unlike metals united together, which consists in contacting a surface of'one such metal with a other metal unlike the first and also unlike silver to insupermolten mass of an formed4 by such supermolten metal with a molten mass containing silver and causing a layer thereof to solidify thereon.

4. The process of producing compound bodies of unlike metals united together, which consists in Contactin a surface oLone such metal with a supermo ten mass of copper and then contacting the coating formed y such supermolten metal with a molten mass containing silver and causing a layer thereof to solidify thereon.

5. The process of producing compound bodies of unlike metals united together, which consists in contacting a ferrous metal base with a non-ferrous metal at a temperature much above its melting point and uniting a layer of a metal comprising silver to the treated base.

6. The process of producing compound bodies of unlike metals united together, which consists in contacting a ferrous metal base with copper at a above its melting point and uniting a layer gf a metal comprising silver to the treated ase.

7; The process of producing compound bodies of unlike metals united together, which consists in contacting a ferrous metal base with supermolten cop er'f and thereby forming a coating on the sur ace of such base, and then contacting such surface with molten silver and causing a layer thereof to solidify thereon.

8. The process of producing compound bodies of unlike metals united together, which consists in contacting a ferrous metal base with'a supermolten unlike metal and thereby forming a coating on thesurface of such base and then contacting such surface with molten silver and causing a layer thereof to solidify thereon. v

9. As a new article of manufacture, a compound metalbody comprising a ferrous metal ase and a poreless layer of a metal com rising silver united thereto by an interme iate layer of metal of high melting point, said intermediate layer being also poreless and molecularly-united to the metal on either side-at all points between abutting surfaces.

10. As a new article of manufacture, a compound metal body metal base and a poreless layer of silver united thereto by an intermediate layer of metal of high melting point, said intermediate layer being also oreless and being molecularly -united to the metal on either side at all points between abutting surfaces.

11. As a new article of manufacture, a compound metal body com rising a ferrous metal base and a poreless Iiayer of a metal comprising silver united thereto by an intermediate layer of copper, said intermediate layer of copper being itself molecularlysilver and" then contacting the coating i united both to said ferrous metal base and to temperature much comprising a ferrous united to an intermediate layer of a third metal.

15. As a new said layer of metal comprising silver at all a points between abutting surfaces.

s a new article of manufacturefa compound metal body comprisin a ferrous metal base and a poreless layer ofsi ver united thereto by an lntermediate layer sald united to an intermediate layer of a third metal of high melting,r point by a union resisting temperature changes, cutting tolls and mechanism stresses, said ferrous base s a new artlcle of manufacture, a l and silver and intermediate coatings having rising a metal been extended together.

an un ike metal, each In testimony whereof I afiix my signature,

comprising silver and lnseparably molecularly-united to an interl in the presence of two witnesses. mediate layer of metal unlike both. J OliN F. MON N OT.

14. As a new article of manufacture, a com- Witnesses:

pound metal body comprising silver and an BYRON E. ELDRED, unllke metal each inseparably molecularly- K. P. MCELROY. 

